Fig. 3

Fig. 3

Controls for the method of laser cell ablation on fin regenerate. Pictures of fin rays were taken before (A, C and E) and immediately after (B, D and F) laser ablation of different cell types of the fin. (A) Shha:gfp-expressing cells in two rays of the 2.4shha:gfpABC#15 transgenic line at 2 dpa. (B) After laser ablation of the cells shown in (A), GFP fluorescence disappears. (C and D) Bright field images of the rays shown in (A and B), respectively, show no visible damage to the tissue following laser ablation. (E) A few epidermal cells of the fin regenerate were labeled by injection of DiI. (F) DiI fluorescence disappears following laser ablation of the targeted cells (arrows in E and F). (G) Fluorescent image of a fin regenerate following ablation of the GFP positive cells in one ray. (H) In situ hybridization immediately after laser ablation of the fin shown in (G) shows shha expression in each fin ray except in the ray on which ablation has been performed. (I and J) In situ hybridization on longitudinal sections of a fin ray with col10a1 probe. (I) Before ablation, col10a1 is expressed in the basal layer of the epidermis (where shha:gfp is also expressed) and in the adjacent scleroblasts. (J) Following ablation of the GFP positive epidermal cells, col10a1 expression in the basal epidermal cells disappears, while col10a1 expression in the scleroblasts remains unchanged. Arrows in (A–H), and the blue brackets in (I and J) indicate the cells targeted for laser ablation. Scale bar in panels I, J = 20 μm.